Appearance:

Adults unmistakable. White head with bold black markings and orangy brown back. Even more striking in flight, with white wedge on back, large white patches at base of wings, white wing-bars and black and white tail. Juvenile and winter plumage birds with similar white patches, but with darker head and greyish, dark brown back. Underside always pure white. Leaves a robust and compact impression, with heavy bill and square head.

Sound:

Characteristic call: An explosive, hard, resonant and short "koi" or "kott" with a peculiar timbre, usually given in rapid or accelerating series. Alarm call/song more "wader-like", a staccato "kuvi-kuvi-vit-vit-vitua".

Alarm call:

Distribution:

Wikipedia: map (se also Xeno-canto below)

Ecology:

Birdlife ecology

Links:

Observation.org Latest observations

Video IBC

Image search Flickr NB! May give other species

Sound search at Xeno-canto

Featherbase

CC

Sounds:Recorded by Niels Krabbe,http://www.xeno-canto.org ,CC license

Appearance:

Differs from Arctic Tern in longer head, and more orangy red, rather than deep red, bill. Tip of bill usually black. Legs longer, but tail streamers shorter than AT. Underparts of primaries with diffusely bordered dark trailing edge (sharply bordered in Arctic Tern). Upper side of primaries with dark wedge (less apparent in winter). Secondaries opaque. Crest more apparent than in Arctic Tern and underside whiter. Juveniles with buff back.

Sound:

Similar to Arctic Tern but deeper. Lacks latter's high pitched "tip-tip-tip" call, and the drawn out "kree-aaahh" call falls more distinctly in pitch.

Call:

Distribution:

Wikipedia: map (se also Xeno-canto below)

Ecology:

Birdlife ecology

Links:

Observation.org Latest observations

Video IBC

Image search Flickr NB! May give other species

Sound search at Xeno-canto

Featherbase

CC

CC-sound:Eetu Paljakka, Licence,Link.